Hi guys...
I know that Bosch's batteries are 36 volt, and Lithium Ion....but I was curious if anyone knows more about the chemistry. How many cells does the 500 Wh have in it? I was also looking for a good spec sheet on them, but can't seem to find anything. Does anyone know how good their chargers are? I was going to try and use the Satiator charger instead, just because it is such a good charger. I would need to remove the plug of the charger and make an adapter as the Bosch plug is proprietary, in an oval shape. I would assume that I would need to know the low-end and high-end cutout voltage too...hence the schematic.

Bosch is a closed system, no tampering. They usually use samsung cells (300wh pack). These you can open and you could connect the satiator to measure the capacity. However their later batteries are sealed and tamper proof. No one has ben able to repair them or make copies, yet. I have bought a few 300 and 400Wh packs that i will experiment on. Any knowledge about the bosh batteries pack are appreciated. i also buy them used/dead packs.

I operate a battery repair shop in Stockholm, Sweden called batteridoktorn (The Battery Doctor).

Bosch is a closed system, no tampering. They usually use samsung cells (300wh pack). These you can open and you could connect the satiator to measure the capacity. However their later batteries are sealed and tamper proof. No one has ben able to repair them or make copies, yet. I have bought a few 300 and 400Wh packs that i will experiment on. Any knowledge about the bosh batteries pack are appreciated. i also buy them used/dead packs.

Hi! would like to replicate Bosch BMS protocol to use custom packs, got any info?
Looks like Chinese manufacturers have done it, as they are selling battery clones. but cannot find any info.

they use basically the same system as several bike sellers in my country (gazelle and sparta). if you cut a balance wire of disconnect the main lead of the board it will basically wipe the memory of the chip and make the control board dead with no way to recover.
once a board enters a fault mode it locks up and refuses service. it is designed this way from the start. some companies go one step further and use the comm lines of the bms to talk to the controller and "mate" with them so mounting a different battery will not work, you need to go to a certified dealership to buy a new 700 euro battery and program it in.
so far i was able to "repair" 2 batteries by simply soldering on extra wires and bypass the mosfets on the board. not neat but it is the only way to recover them when they enter a fault mode that is no longer present.

The Battery Doctor,
once you have Bosh battery pack opened, can you make close up pictures of a board so we can identify processor on this board?
so we can look up data sheet to learn more how the board works with rest of BOSH drive?
for sure BMS must communicate with display, that is for sure
BOSH shows real SOC based on Columb count - what does it tell us?

I just changed the cells in two 2014 Bosch 400Wh batteries, some time ago I did the same for a 500Wh. I just solder another battery in parallel on the BMS (just + and -, not the phases) while I disconect the battery I have to change the cells on. Before that I put it down at 35,4V as the new cells I put in are at 3,54V each. We bought an adaptator from https://dokteraccu.nl/ that alows us to test the capacity of the batteries, and to bring them to desired voltage .
The cells in the 400Wh are samsung 29E (LG before that, I don't know the exact type), and in the 500 Wh I think they were Sanyo's but I'm not sure anymore...
Unfortunately I don't own any smartphone to put you pictures of the BMS, but I'll try to "stole" my boss's one or to bring my camera.
I already repaired several batteries from Bosch without any problem, from the old type or the new one. But if the BMS is out, the battery won't work anymore and you will have to pay the 700€ to get a new one

Back in the day the Bosch BAT836 cordless tool packs were some of the first 18650 batteries used by ebikers! But that is also when Bosch was alot cheaper. You could buy four packs and put them together and have a strong sony 18650 battery pack fairly easy, most even used the Bosch chargers too! This was a big performance upgrade from the 2c laptop cells and much lighter than A123 26650 which was the strongest.

Hi guys!
I'm doing pretty the smae thing right now. I have two powerpack Bosch 400Wh, quite new, but withou any electric bosch system.
So, I want to use my batteries for other systems and motor.

As you know, no tension is delivered from the battery if it's not a Bosch system, but we can maybe hack the thing ?
At the connector, with the Plus and Minus cable, there are 3 thin cables. Maybe by connecting them together, it will work ?
3 cables = 1 for the ground, 1 for the charge, 1 for the discharge ?Or is it just too easy?
Some pics :

You can always cut main leads I mean wires +/- from the BMS board, remove it and use only strings of cells with no BMS,
circuit board shown is much useless without commnunicating with rest of BOSH system.
on every power up display/controller makes handshake with this electronics.

Just connect the 3 wires is too simple There is a communication between the battery and the rest of the system. A said above, we bought an adaptator that allows us to drain current from the battery without beeing on a bike, but it is quite expensive (round 150€). If you won't use them on a Bosch bike, just buy a simple chinese BMS to replace this one...

I just got a 500Wh battery appart, the cells in it are LG INR18650-MJ1 3500mAh (in another one I worked on, I am quite sure they were Sanyo's. But in the 400Wh you sometime see Samsung 29E or LG too). I will try to take pictures on wednesday. I don't know who died first, the cells or the BMS, but the pack is at 9V. I tried to pull it to 30V with another pack, to see if the BMS would "wake up", but it haven't work...

Mmmh thanks for the informations.
I'm not an expert in electronic or not enough I think to change a BMS... Unless it's pretty simple?
We have to spot each cells and weld the wire at the good position in the BMS no?
You have idea of what BMS I can use?
Thanks!

It's quite easy, just a bunch of wires to solder (in the right order). This kind of BMS would do the job: here
At least your battery will be protected, and you too... I'm sure there are plenty of subjects here or on the wiki that explain you how to install it.

Here are some pictures of the 500 and 400 Wh Bosch batteries. I tried to take pictures of the chip on the BMS, but the writings are hard to read (even in real life).